P2 Revision Booklet

Force and Acceleration

Easy (Grade D/E)

Q1.          A high-speed train accelerates at a constant rate in a straight line.
The velocity of the train increases from 30 m/s to 42 m/s in 60 seconds.
(a)     (i)      Calculate the change in the velocity of the train.
...............................................................................................................
                                        Change in velocity = .............................. m/s
(1)

(ii)     Use the equation in the box to calculate the acceleration of the train.

Show clearly how you work out your answer and give the unit.
Choose the unit from the list below.
 
m/s	m/s2	N/kg	Nm	

...............................................................................................................
...............................................................................................................
                                     Acceleration = ..................................................
(2)

(b)     Which one of the graphs, A, B or C, shows how the velocity of the train changes as it accelerates?
Write your answer, A, B or C, in the box.

 
    A	
 
         B	
 
             C	

Graph		

(1)
(Total 4 marks)
 Q2.          The diagram shows an adult and a child pushing a loaded shopping trolley.

(a)     (i)      What is the total force on the trolley due to the adult and child?
...........................................................................................................................
(1)
(ii)     Which one of the terms in the box means the same as total force?
         Draw a ring around your answer.
 
          answer force          mean force        resultant force	

(1)

(iii)     The trolley is pushed at a constant speed for 80 metres.
         Use the equation in the box to calculate the work done to push the trolley 80 metres.
 
work done = force applied × distance moved in direction of force	

         Show clearly how you work out your answer.
...........................................................................................................................
...........................................................................................................................
Work done = ............................................................
(2)

(b)     Complete the following sentences by drawing a ring around the correct word in each of the boxes.

(i)       The unit of work done is the	joule
newton
watt	 
.	

(1)

 
 
(ii)      Most of the work done to push the trolley is transformed into	heat
light
sound	 
.	

(1)
(Total 6 marks)
 Q3.          (a)     The model bus is being pushed on a table.

(i)      At first the pushing force does not make the model bus move. Explain why.
...........................................................................................................................
...........................................................................................................................
(1)

(ii)     Write down two things that happen as the pushing force increases.
1 ........................................................................................................................
...........................................................................................................................
2 ........................................................................................................................
...........................................................................................................................
(2)

(iii)     Complete the formula by choosing the correct words from the box.
 
acceleration             distance moved        force applied
speed                        time taken	

         Work done on
the model bus            =          ......................................          × ......................................
(2)

(b)     In this situation, the car driver needs to stop the car in the shortest possible distance.

(i)      Complete the table by putting ticks () to show which factors would make the stopping distance greater. The first one has been done for you.
 
Factor 	Tick (  ) makes stopping
distance greater 	
brakes are old and worn 	 	
car is travelling fast 	 	
driver has been drinking alcohol 	 	
four new tyres are fitted 	 	
hot, dry, sunny weather 	 	
ice on the road 	 	

(3)

(ii)     Complete the sentence by writing the correct words in the spaces.
         The car will skid if the braking force is too big compared with the friction between
         the car’s .................................... and the .................................... .
(1)
(Total 9 marks)
 Q4.          A small object falls out of a balloon.

Choose words from the list to complete the sentences below.
friction                             gravity                                           air pressure
accelerates                      falls at a steady speed                   slows down
•        The weight of an object is the force of ............................................ which acts on it.
•        When you drop something, first of all it ............................................... .
•        The faster it falls, the bigger the force of ........................................... which acts on it.
•        Eventually the object ............................................. .
(Total 4 marks)
 Forces and acceleration-Mark scheme

M1.         (a)      (i)     12
1

(ii)     0.2
allow 1 mark for their (a)(i) ÷ 60 and correctly calculated
1

m/s2
accept correct unit circled in list
accept ms−2
do not accept mps2
1

(b)     B
1
[4]
 M2.          (a)     (i)      50 (N)
ignore any units
1
(ii)     resultant force
1
(iii)     4000
accept their (a)(i) × 80 correctly calculated for 2 marks
allow 1 mark for correct substitution i.e. 50 × 80 or their (a)(i) × 80
ignore any units
2

(b)     (i)      joule
1
(ii)     heat
1
[6]
 M3.          (a)     (i)      the pushing force balanced by the friction
accept the pushing force equals friction or pushing force is too small or frictional force is too great
1
(ii)     any two from
an unbalanced force acts on the model bus
the model bus moves
in same direction as pushing force
accept forwards
and will speed up
2

(iii)     force (applied)
any order
1
distance ( moved)
1

(b)     (i)      car is travelling fast
1
driver has been drinking alcohol
1
ice on the road
1

(ii)     tyres and road / ground
1
[9]
M4.          •        gravity
•        accelerates
•        friction
•        falls at a steady speed
each for 1 mark
[4]